Re: Multicast Understanding

its probable that after the first packet u switchover to source path
tree[SPT] . try with ip pim spt-thres infini

On Sun, Oct 11, 2009 at 6:10 PM, karim jamali <karim.jamali_at_gmail.com>wrote:

> Dear Divin,
>
> I didn't get you clearly. Are you saying that both routers can forward @
> the same time as this is what is happening with me?
> Please explain more. The thing that is happening with me is that both
> routers (R2,R3) are forwarding multicast traffic to the presumed client
> (R4). However the thing is that I thought that only one forwarder will be
> elected on a common subnet and this router will forward multicast traffic to
> the subnet.
>
> Can you please explain in more detail?
>
> Thank You
>
> Best Regards,
> On Sun, Oct 11, 2009 at 3:08 PM, Divin Mathew John <divinjohn_at_gmail.com>wrote:
>
>> yep.
>>
>> highest is the DR. but lowest ip address needn't necessarily forward
>> multicast traffic onto the broadcast domain.1
>>
>> The assert election criteria are as follow in decreasing order of
>> priority:
>>
>> 1- administrative distance to the source S (10.10.10.1)
>>
>> 2- Cost of the route to S (10.10.10.1)
>>
>> 3- Highest multicast interface IP address.
>>
>> refer
>> http://cciethebeginning.wordpress.com/2008/07/16/pim-assert-message/
>>
>> On Sun, Oct 11, 2009 at 3:59 PM, karim jamali <karim.jamali_at_gmail.com>wrote:
>>
>>> Dear Gents,
>>>
>>> I have a confusion regarding multicast. I am running a sparse-mode
>>> scenario
>>> which is shown in the attached visio file.
>>> R1 s1/0 -->R2 s1/0 (12.0.0.0/24)
>>> R1 s1/1 -->R3 s1/0 (13.0.0.0/24)
>>>
>>> R2 fa0/0-->R3 fa0/0(23.0.0.0/24)
>>> R2 fa0/1 -->R3 fa0/1 -->R4 fa0/1 all on the same subnet (123.0.0.0/24)
>>>
>>> Pim Sparse mode is running on all the common interfaces & neighbor
>>> relationship is formed. On R2, I have a loopback (2.2.2.2) which is the
>>> RP
>>> of the my network.
>>>
>>> Note that I am running OSPF everywhere.
>>>
>>> The confusion is related to the common subnet of R2,R3,R4. From what I
>>> understood, on every common subnet one Querier,and one Forwarder is
>>> elected,
>>> and one Designated Forwarder is Elected.As far as I understand, the
>>> Querier
>>> is the one sending queries asking if anyone wants to join a certain
>>> group.A
>>> forwarder is the one forwarding the stream to the subnet. The designated
>>> router as far as I understand is the the first layer 3 device which knows
>>> about the stream from the streamer,and sends a register message to the RP
>>> notifying it that a source exists. Please correct me if any of my
>>> concepts
>>> is wrong.
>>>
>>> The router with the lowest IP address is the querier and the one with the
>>> highest IP address is the forwarder. In the scenario I have shown, R1 is
>>> the
>>> source, R2's loopback is the RP and R4 ethernet interface has joined a
>>> group
>>> (239.1.1.1). When I ping from R1, I notice that the stream on R4 is being
>>> received from both R2,and R3?Does this break the concept of forwarder?
>>>
>>> I would be grateful for any help.
>>>
>>> Best Regards,
>>>
>>> KJ
>>>
>>>
>>> Blogs and organic groups at http://www.ccie.net
>>>
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>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>> --
>>
>>
>> Umberto Eco <http://www.quotationspage.com/quote/320.html> - "I felt
>> like poisoning a monk."
>>
>
>
>
> --
> KJ
>

-- 
Sent from Karnataka, India
Umberto Eco <http://www.quotationspage.com/quote/320.html>  - "I felt like
poisoning a monk."
Blogs and organic groups at http://www.ccie.net